<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="UTF-8">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <title>Document</title>
  <style>
    .box{
      width: 500px;
      height: 500px;
      background-color: antiquewhite;
      /* position: relative; */
      /* display: flex;
      justify-content: center;
      align-items: center; */

      /* display: grid;
      justify-content: center;
      align-items: center; */

      /* display: table-cell;
      text-align: center;
      vertical-align: middle; */

    }
    .wrap{
      /* display: inline-block; */
      width: 200px;
      height: 200px;
      background-color: #5cd552;
      /* position: absolute;
      left: 50%;
      top: 50%; */
      /* transform: translate(-50%, -50%); */
      /* margin-left: -100px;
      margin-top: -100px; */

      /* margin-left: 150px;
      margin-top: 150px; */

      margin: 0 auto;
    }
  </style>
</head>
<body>
  <div class="box">
    <div class="wrap">hello world</div>
  </div>
</body>
</html>